body:newGridView.count(//Create a grid with 2 columns. If you change the scrollDirection to//horizontal, this would produce 2 rows.crossAxisCount:2,//Generate 100 Widgets that display their index in the Listchildren:newList.generate(100, (index) {returnnewCenter( child:newText('Item $index...
添加了一个_listKey变量,它是一个GlobalKey<AnimatedListState>类型的键。这个键将用于访问AnimatedList的状态,从而能够在列表发生变化时执行插入/删除操作。 在_addItem函数中,在添加新项目到_items列表之后,还调用了_listKey.currentState?.insertItem(...)方法。这个方法可以通知AnimatedList插入了一个新项目,从而触发...
原文https://medium.com/@kaushikidum29/10-most-useful-flutter-widgets-e64e74229a2a 1. Slider 我们使用滑块小部件来更改值。因此,需要将值存储在变量中。这个小部件有一个滑块类,它需要 onChanged ()函数。当我们改变滑块位置时,这个函数将被调用。 示例代码 Slider( value: _value.toDouble(), min: 1.0...
String randomString = String.fromCharCodes( List.generate( 10, (index) => 97 + Random().nextInt(26), ), ); // 改变用户名 UserProfileState.of(context)?.changeUserName(randomString); }, child: const Text('改变名称'), ), ], ), ); } randomString 是一个随机的 10 个字母 通过User...
}).toList(), ), ), ); } } class Item { Item({ required this.expandedValue, required this.headerValue, this.isExpanded = false, }); String expandedValue; String headerValue; bool isExpanded; } List<Item> generateItems(int numberOfItems) { return List<Item>.generate(numberOfItems, (...
Widgetbuild(BuildContext context){returnnewScaffold(appBar:newAppBar(title:newText('Grid Page 1 demo'),),body:newCenter(child:buildGrid(),),);}List<Container>_buildGridTileList(int count){returnnewList<Container>.generate(count,(int index)=>newContainer(child:newImage.asset('images/pic${inde...
Flutter 布局的核心机制是 widgets。在 Flutter 中,几乎所有东西都是 widget —— 甚至布局模型都是 widgets。你在 Flutter 应用程序中看到的图像,图标和文本都是 widgets。此外不能直接看到的也是 widgets,例如用来排列、限制和对齐可见 widgets 的行、列和网格。
of [WidgetsApp]./// The boolean arguments, [routes], and [navigatorObservers], must not be null.constMaterialApp({Key key,this.navigatorKey,this.home,// 主页面组件this.routes=const<String,WidgetBuilder>{},this.initialRoute,this.onGenerateRoute,this.onUnknownRoute,this.navigatorObservers=const...
this.onGenerateTitle, this.color, this.theme,// 主题 this.darkTheme, this.themeMode = ThemeMode.system, this.locale, this.localizationsDelegates, this.localeListResolutionCallback, this.localeResolutionCallback, this.supportedLocales = const <Locale>[Locale('en', 'US')], ...
In this list, each child element is an expansionpanel widget. In this list, we cannot use different widgets as child windows. We can handle state adjustments (expansion or collapse) of things with the help of the expsioncallback property. ...